Kinda panicking about my band

So I'm in a band, shocker I know, I got in because someone overheard me playing the guitar, I've been playing guitar for 3 years and I'm a lead guitarist, yeah? I've been doing bass for 5 months and they want me too be their bassist?? I'm not bad but I've practised for about 1 hour for a total of a week during the holidays, I don't wanna get kicked out??? Errrr slightly struggling because I'm back tommorrow...